Mechanism for the automatic control of speed change transmissions of motor vehicles



March 2, 1943. ou ou 2,313,003

MECHANISM FOR THE AUTOMATIC CONTROL OF SPEED CHANGE TRANSMISSIONS 0F MOTOR VEHICLES Flled Jan 11, 1940 3 Sheets-Sheet 1 ma g Qm Qw ifvauyafou fi: Attorney March 2, 1943. J. NOUGAROU 2,313,003 MECHANISM FOR THE AUTOMATIC CONTROL OF SPEED CHANGE TRANSMISSIONS 0F MOTOR VEHICLES Filed Jan. 11, 1940 s Sheets-Sheet 2 /4 /5 FEE-i I-\'\ W Q /7 .9/ z 7/ /a l/ Inventor I Alto rn ey.

March 2, 1943. J NQUGAROU 2,313,003

' MECHANISM FOR THE AUTOMATIC CONTROL OF SPEED v CHANGE TRANSMISSIONS 0F MOTOR VEHICLES Filed Jan. 11, 1940 3 Sheets-Sheet 3 IIIIII 1 i Z llrllll. VIIIIIIIIJ ',1,,

Nouya rou Attorney Inventor- Patented Mar. 2, 1943 MECHANISM ron 'rnr. AUTOMATIC coN- TROL OF SPEED CHANGE TRANSMIS- SIONS OF MOTOR VEHICLES Jacques Nougarou, Paris, France; vested in the I v Alien Property Custodian Application January 11, 1940, Serial No. 313,336

In France November 3, 1937 11 Claims.

My invention relates to a mechanism for the automatic control of a speed change transmission of motor vehicles, and the present application is a continuation-in-part of. application Serial No.

237,613, filed October 29, 1938.

More particularly, it is applicable to speed change transmissions of the type including a plu rality of electromagnets which may be energized in different combinations and will then set up difi'erent ratios of transmission. Motor vehicles equipped with such transmissions have been in practical operation for a number of years. In these vehicles, however, the electromagnets of the transmission were controlledby a hand lever enabling the driver to shift the gears as desired by simply setting this lever to different positions. Also, attempts have been made of controlling the transmission automatically so as to meet the requirements arising in the operation of the vehicle.

The objects of my invention are to improve such a control mechanism so as to facilitate the operation of the vehicle and to better meet the requirements as they arise under different conditions of operation; to simplify the control mechanism; to enhance its reliability and to render it fool-proof.

A more specific object of my invention is to control the transmission exclusively from the accelerator pedal and from an element responsive to the speed of the vehicle and yet to enable the operator to arbitrarily select one or the other ratio of transmission when driving at a speed varying between certain limits. When driving at a speed of twenty miles per hour, for instance, the operator shall have the choice between the direct gear or the next lower gear as required under the particular driving conditions. I attain this object by a mechanism in which the contacts controlling the transmission are actuated by the relative movement of two members, one being connected with the accelerator lever of the vehicle and the other one moving in proportion to the speed of the vehicle.

Other objects are to ensure that the accelerator lever can act on the coordinated member only in its extreme positions; to provide means preventing any gear change as a result of the movement of the accelerator lever in the initial stage of this movement from resting position; to provide means preventing the transmission from being shifted to a higher gear when the accelerator pedal of the car is released but shifting the transmission to a higher gear upon redepres'sion of the accelerator pedal after a preceding return thereof to resting position; -I attain these objects by the cooperation of the two above-mentioned members controlling the electrical contacts.

-A further object is the provision of means adapted to maintain the energization of a selected transmission magnet for "the period of time required to complete the speed change. This object is attained by the use of slow-acting relays which, when energized, will close or interrupt a circuit after expiry of a predetermined period only. In this manner, the required shifting time is gained after energization of the relay. These relays may either short-circuit resistances arranged in series with the electromagnets of the transmission or they may close the energizing circuit of these electromagnets upon expiry of a predetermined period only. This period may be adjusted by variation of the energizing current of the slow-acting relay. Owingto the provision of such slow-acting relays, shocks incident to the shifting to lower gears will be avoided.

Further objects of my invention will appear from the description of a preferred embodiment thereof and the features of novelty will be pointed out in the claims.

In the drawings,

Fig. 1 is an elevation of the two contact controlling members, partly in section;

Fig. 2 is a plan-view of part of the mechanism shown in Fig. 1 illustrated on a smaller scale;

Fig. 3 is a partial axial section through the transmission and a circuit arrangement of the controlling members thereof;

Fig. 4 is an elevation of .a slow-acting relay; and

Fig. 5 a relay mechanism for use in connection with the control means shown in Fig. 3.

While my invention is applicable to any transmission shiftable by the energization of electromagnets in difierent combinations, it will be described hereinafter with reference to its application to a transmission which is known under the name Cotal transmission. A longitudinal partial section through this transmission is shown in Fig. 3.

The driving shaft 234 of this transmission is connected with the engine either directly or through a clutch. The driven member geared to the wheels of the vehicle is formed by a hollow shaft or sleeve 240 rotatably journalled on the shaft 234.

Thetransmission consists of two epicyclic gears designated as a whole by 2M and 242 each comprising three relatively rotatable elements, to wit an inner sun wheel 243, and 244 respectively, a carrier 245, and 246 respectively, of a plurality of planetary gears 241, and 248 respectively, meshing with the inner sun wheel and an outer gear 249 and 258 respectively, meshing with the planetary gears. An electromagnetic clutch and brake are coordinated with each epicyclic gear 24| and 242 and are adapted to establish a rigid connection between one of the three elements, to wit 243 and 244 respectively, either with the gear casing 16 or with the second element 249 and 246 respectively, while the third element 245 is rigid with the third element 258 of the other epicyclic gear.

One of the three elements of each epicyclic gear, to wit 249, and 246 respectively, is connected with the driving shaft 234, and the driven shaft 248 respectively.

Each of the two electromagnetic clutches and brakes comprises two circular electromagnets- 8|, 82, and 83, 84 respectively, one of which is fixed to the casing 16 while the other one is fixed to the gear element 249 and 246 respectively. The two electromagnets embrace an axially shiftable annular armature 25| which will be attracted by one or the other of the two electromagnets to establish a frictional engagement therewith as soon as the magnet coil is energized.

As this transmission is well-known, it is believed that a detailed description thereof may be dispensed with. It is believed sufilcient to state that the first speed requires the simultaneous energization of the electromagnets 82 and 83 fixed to the casing 16, whereby the two armatures 25| and the gear elements 243 and 244 rigid therewith will be arrested and held stationary. As a result, the

gear element 245 will revolve at a reduced speed compared with that of the driving shaft 234 and the element 249 connected therewith. This reduced speed is transmitted to the element 258 causing the element 246 connected with the driven shaft 248 to revolve at a still slower speed.

Shifting the transmission to second gear requires the simultaneous energization of the magnets 82 and 84. The gear element 258 will still revolve at the same reduced speed as before but this speed will be transmitted to the driven shaft 248 as the three elements 244, 246 and 258 will revolve in unison owing to the attraction of the armature 25| by the magnet 84.

The third gear requires the energization of the electromagnets 8| and 83. The first epicyclic gear will be locked owing to the attraction of the armature 25| by the electromagnet 8| causing the three elements 243, 241 and 249 to revolve in unison with the speed of the driving shaft 234. This speed will be reduced in the second epicyclic gear in which the element 244 is held stationary owing to the attraction of the armature 25| by the electromagnet 83.

The fourth or direct gear requires the energization of the electromagnets 8| and 84, whereby both epicyclic gears are locked causing all of their elements to revolve in unison.

The mechanism for automatically controlling the selective energization of the magnets 8|84 comprises a plurality of electrical contacts and a contact-actuating element. The electrical contacts are constituted by two opposed groups of leaf springs 52, 53 and 62, 63, 64. As shown in Fig. 3, the springs of each group are arranged in a staggered relationship in such a way that the spacing of the three pairs of opposed leaf springs is the same. The actuating element comprises a conductive member 65 which is movable in a direction parallel to the leaf springs and is adapted to contact therewith. The width of the member 65 is substantially the same as the spacing of the opposed springs, as will appear from Fig. 1. Each group of leaf springs is attached to a block 66 of insulating material. The two blocks 66 are carried by a threaded spindle 61 and are held at an adjustable distance thereon by nuts 68. The spindle 61 is attached to a member 69.

Before explaining how the relative movement of the two members 65 and 69 will cause the electromagnets 8|84 to be selectively energized, I shall describe the means for displacing the members 65 and 69 in dependence on the condition of operation of the vehicle.

To the frame of the instrument, there is suitably connected a cylinder 98 having flanges 9| provided with openings in which a rod I8 is guided. The cylinder 98 slidably supports a piston 9. The rod l8 and the piston 9 are fixed to the support 69 and thus guide the same in a direction parallel to the leaf springs 5| etc. The rod M has two adjustable abutments II and I2 preferably in form of adjustable nuts limiting its stroke. This stroke is preferably of the length a indicated in Fig. 3.

A lost-motion connection is provided between the member 69 and the accelerator lever of the vehicle. This lever 288 is diagrammatically shown in Fig. 1 in a partly depressed position. It is connected by a Bowden wire IT with a helical spring I5 attached to one of the flanges 9|. The sheath l6 of the Bowden wire extends from a bracket 92 mounted in the neighbourhood of the pedal 288 and to a bracket 93 attached to the frame of the instrument in the neighbourhood of the cylinder 98. Hence, it will appear that any movement of the pedal 288 will be imparted to longitudinal movement of the Bowden wire IT.

This Bowden wire extends through a suitable opening of the member 69 and carries two abutments I3 and i4 on either side thereof. The distance of the abutments I3 and H which is preferably rendered adjustable, is considerably larger than the width of the member 69, whereby lostmotion is provided for between the pedal 288 and the member 69. The abutments l3 and H are adjustably clamped to the Bowden wire I! by screws.

Moreover, two stops l8 are attached to the Bowden wire each stop being adapted to control electrical switches Nd, and 12d respectively, each comprising a stationary leaf spring l9 and a movable leaf spring 28, the latter contacting with the stop l8. These stops are so arranged that when the pedal 288 is in resting condition in which the throttle of the engine is closed, the contacts l9 and 28 are in circuit closing condition. Upon a slight depression of the pedal 288, however, the contacts are separated, long before the abutment l4 will engage the member 69.

Owing to the lost-motion between the abutment I4 and the member 69, the accelerator 288 can be depressed the greater part of its stroke before the member 69 will be shifted towards the left from the position shown in Fig. 1. When subsequently the pedal 288 is released, it may closely approach its resting position before the stop l3 will engage the support 69 and will return the same to the normal position shown in Fig. 2. In Fig. 1 the parts are shown at the instant where the member 69 is in displaced condition and is engaged by the abutment |3 to be restored on the continued upward motion of the pedal 288. It will be noted that the contacts I9, 28 are still opened but will be closed when the member 69 will be restored.

The function of the contacts I9, 28 will be deof Fig. 3.

scribed later with reference to the circuit diagram 94 with a member 20: which is slidably mountedupon a suitable guide extending parallel to the springs etc. This guide comprises a shaft 202 and a guiding rod 200 attached to a bar 204 forming part of the frame of the instrument. The shaft 202 is Journalled on a pivot 85 attached to th bar 204 and in a Journal 80 attached to a bar 208 also forming part of the frame of the instrument.

The member 208 is moved from its normal position shown in Fig. 1 towards the left an amount corresponding to the speed of the vehicle. For this purpose, the following means are provided: A flexible shaft 51 suitably connected with the cardan shaft or another element moving in proportion to the speed of the vehicle is connected to the shaft 202 by a suitable clutch 98. A spider member 2 I0 fixed to the shaft 202 by a pin 80 and a second spider member I00 carried by a flanged sleeve 201 loosely mounted on the shaft 202 are connected by a plurality of toggle links IM and I02. The pivot pins I03 of the toggle links carry weights 206. Helical springs 2I4, 2l5 and M8 are interposedbetween the spider member M8 and the sleeve 201 and the spidermember I00. when the shaft 202 revolves, the toggles tend under the centrifugal force of the weights 206 to collapse and to compress the springs 2 to 2I8, whereby the flanged sleeve 201 will be displaced towards the left. The, flange of the member 201, however, is embraced by the member 208 and by a plate I04 connected thereto. actuator 65 assuming the position shown in Fig. 1 when the vehicle is standing, will move towards the left, as the speed of the vehicle increases.

From the foregoing description it will be realized that the relative displacement between the contact-support 61 and the actuatingmember 55 is the same as the relative movement of the members 69 and 208. While this is achieved in the present embodiment by the attachment of the contact-support 61 to the member 59 and of the contact-actuator55 to the member 208, it is obvi- Therefore, the

iable -resistance02, and 33 respectively (Fig. 3).

ous that numerous other arrangements will have 1 the same effect. Hence, it should be kept in mind that. for the proper operation of the mechanism it is material only that the relative motion of the contact-support 51 and the actuator 65 should be the same as the relative motion between the members 59 and 208.

In the circuit diagram illustrated in Fig. 31

have diagrammatically indicated the various positions of the actuator 55 relative to the leaf springs 5|, 52, 53, 63, 52, 64, by rectangles shown ina different fashion. The rectangle shown in full lines indicates the relative position resulting in the setting of the transmission to the 1st gear. The rectangle shown in dotted lines is the 2nd gear position, th rectangle shown in dash-anddotted lines is the 3rd gearposition, while the rectangle shown in stippled lines is the 4th or'direct gear position.

The control mechanism. includes two relays designated as a whole by H and 12 each comprising a single armature He and 12c, respectively,

capable of assuming one or the other of two po sitions. The armatures are located between two opposed electromagnets 1Ia, 1": and 12a, 12b, respectively, which,-when simultaneously energized or de-energlzed, will leave the armature in what- .ever position the same may be. If one of the two armatures, however, is energized alone, it will attract the armature unless the same should be already in attracted position. Moreover, each of the two relays includes a short-circuit shunted across its windings and including the interrupter 1 I d, and 12d respectively, mentioned hereinabove.

Moreover, the control mechanism includes two relays 05 and I85 each having a single working contact 01, and I81 respectively, and two slowacting relays 22 and 80, 0|. The relay 30, 8| has two windings while the relay 22 has a single winding only. The armatures 23 and 20 of these relays are connected with means serving the purpose of delaying a response of the relay to energization ing of the contacts 21 will be delayed by the damping effect exerted by the viscous liquid on the plate 24.

The period of delay depends on the voltage applied and, therefore, may be adjusted by a ver- The operation of the mechanism is as follows:

(1) Assuming that the engine of the vehicle is idling and that the vehicle and the accelerator pedal are at rest, the member 200 and the actuator 85 carried thereby assume their normal position shown in Fig. 1. Similarly, the leaf springs 5|, 52, 53, 52, 63, 04 assume their normal righthand position with reference to Figs. 1 and 3. The relative position is indicated in Fig. 3 by the rectangle shown in full lines. It will be noted that the springs 02, 83, 84 contact with the actuator while the three other springs 5|, 52, 53 do not contact therewith. The two contacts ":1 and 12d are in closed condition and short-circuit the windings of the two relays H and 12 leaving the armatures Ho and 120 in whatever position they may be. Under this condition any one of the four speeds may be set up in the transmission.-

The clutch is in disengaged condition permitting the shaft of the engine to rotate while the wire 56, spring 02, actuator 05 and ground. It is to be understood that the actuator is electrically connected with the frame of the vehicle and that the same applies to one terminal of the battery.

(b) Battery, wires 54 and I55, winding 12b, wire I56, spring 03, actuator 65 and ground. In these two circuits the relay windings 'IIb and 1212 are energized and attract their armatures 1 I c and 12c establishing the following circuits:

Battery 15, wire 54, 55, armature 1Ic, wire 51, winding 30, resistance 33, ground. Therefore, the armature 28 of relay 30, 3I is attracted closing its working contact 29. This contact will place the winding of the electromagnet 83 in shunt to the winding 38 and the resistance 33, whereby the electromagnet 83 is energized.

(d) Battery, wires 54, I55, armature 12c, wire I51, relay winding 22, resistance 32, ground.

The armature 23 of relay 22 closes its working contact 21 and the latter places the winding of electromagnet 82 in shunt to the winding 22 and the resistance 32 energizing electromagnet 82.

Therefore, the two electromagnets 82 and 83 are energized resulting in the setting of the transmission to first gear. The increasing speed of the engine causes the automatic clutch to be engaged whereby the vehicle is started in first gear.

(3) It will be assumed for the present that the accelerator pedal is depressed most of its way but not sufllcient'to cause the abutment I4 to engage the member 69 leaving the contact springs in their normal position. As the speed of the vehicle increases, the actuator 65 moves towards the left until arriving at the second gear position shown in dotted lines in Figure 3, in which it has made contact with spring 5| but has interrupted the contact with spring I32. Therefore, the circuit energizing the winding 1 lb is interrupted. However, the circuit established through spring 63 resulting in the energization of the electromagnet 82 is further maintained. It will be recalled that this circuit includes wire I51. A branch I58 of this circuit is connected with one terminal of the winding I85, the other terminal of which is connected to the ground. Hence, the attraction of armature 120 by the winding 12b did not only result in the energization of the relay 22 but at the same time in that of the relay I85 which is still being maintained during the second gear position of the actuator 55.

The armature I86 of relay I85 establishes the following circuit: battery 15, wires 54, 55, winding 1 Ia, resting contact I81 of relay I85, armature I86, wire I59, spring 5I, actuator 65, ground. The relay col Ila is energized andattracts armature 1Ic establishing the following circuit: Battery 15, wires 54, 55, armature 1Ic, wire 58, electromagnet 84.

Hence, the two magnets 82 and 84 are energized at the same time setting the transmission to sec- 0nd gear.

It willbe noted that the winding 3I of relay 30, 3| is arranged parallel to the winding of relay 22 and is, therefore, keptenergized as long as the electromagnet 82 is in operation, that is to say, for the 1st gear position and the 2nd gear position. Hence, the armature 28 closes its working contact 29. In the 2nd gear position this has noeffect, however, since wire 51 is dead.

(4) Upon further increase of the speed of the vehicle, the actuator arrives in the-3rd gear position in-which it makes contact with springs 5I and 52 and breaks contact with springs 62 and 63. The circuit of winding 12b is'interrupted at the spring 63. However, a circuit through winding 12a is established by the spring 52 as follows: battery 15, wires 54, I55, wire 58, spring 52, actuator 65, ground. The armature 12c shifted towards the left closes the following circuit: battery 15, wires 54, I55, armature 12c, wire I88, terminal 11 and electromagnet 8| of the transmission. At the same time, the relay 85 is placed in shuntto the electro'magnet 8| and attracts its armature 86 closing the working contact 81, whereby the following circuit is established: battery 15, wires 54, 55, winding 1Ib, wire 56, wire 60, contact 81, armature 86, spring 64, actuator 65, ground. The winding 1Ib included in this circuit attracts armature He and closes the following circuit: battery 15, wires 54, 55, armature 1Ic, wire 51, relay winding 30, resistance 33, ground. As the armature 28 was closed during the second gear position owing to the energization of coil 3I as above described and acts too slow to open the contact 29 in the brief interval between the breaking of contact with spring 63 and the making of contact with spring 52, the establishment of this circuit results immediately without any delay in the energization of the electromagnet 83 through wire 6I. Hence, the two magnets 8I and 83 are energized setting the transmission to 3rd gear.

(5) Upon further increase of the speed of the vehicle, the actuator arrives in the 4th gear position interrupting the contact with the spring 64 and simultaneously establishing that with spring 53. As a result, the two windings 1Ia and 12a are energized through circuits closed by the springs 52 and 53 which may be easily traced. Hence, armature He will close the following circuit: battery, wires 54, 55, armature 1 Ic, wire 58, terminal 80, electromagnet 84. The armature 12c closes the following circuit: battery 15, wires 54, I55, armature 12c, wire I63, terminal 11, electromagnet 8I. Hence, the two electromagnets 8I and 84 will be energized simultaneously.

Upon further increase of the speed of the vehicle, the actuator 65 may move farther towards the left but will remain in contact with the springs 5|, 52 and 53 maintaining-the 4th gear position.

(6) It was assumed heretofore that the pedal 28!) was depressed most of its way but not sufficient to cause the abutment l4 to displace the member 69 from its normal position. We shall now consider theeifect of a complete depression, of the pedal. This will result in a movement of the member 69 and of the contact springs carried thereby towards the left limited by engagement of the stop I2 with the flange 9|. As a result, any predetermined relative position of the elements 58 and 65 will be attained at a higher speed only than before. In other words, after a full depression of pedal the transition from one gear position to. the following gear position will occur at a higher speed of the vehicle than after a complete release of the pedal. This means, for instance, that when the car is started with a fully depressed pedal, the transmission will not be shifted from 1st gear to 2nd gear until a speed of, say, 10 miles per hour has been reached as is desirable for a rapid acceleration. If the driver wishs, however, to keep up this speed for some time, as may be necessary in trafilc, he must either depress the pedal not fully or release it temporarily in order to restore member 69. In this event, the transmission will shift from 1st gear to 2nd gear at a much lower speed of, say, 5 miles per hour so that it is in 2nd gear when the speed of 10 miles is reached. This again meets the practical requirements.

Another example will further illustrate this feature of my invention.

It be assumed that the vehicle is running at a moderate speed in 4th gear and that the driver wishes to accelerate the vehicle by shifting back to 3rd gear. In order to do so he must fully depress the accelerator pedal. This results in a displacement of the contact springs from normal position to operated position whereby the relative 3rd gear position oi the springs and the actuator is ,established shifting the transmission to 3rd gear as required tor a rapid increase of the speed. The consequent movement of the actuator 65 will then shift the transmission to 4th gear again. It

may be desirable to return the member 39 to its normal position, for instance, if the operator entirely and then re-depress it partly. just sufli-.

cient to establish the relative 4th gear position 01 the members 65 and 59.

('7) When the speed of the vehicle drops while the pedal 200 is kept depressed, for instance, as

a result of a steep grade of the road, the actu-.

ator 35 will move towards the right and will automatically shift the transmission into a lower. gear. Here again anyone of these shifting operations will occur at a higher speed, after the pedal has been fully depressed and at a lower speed after thepedal has been fully released. A detailed description of the operation may be dispensed with since the circuits established are the same as those described in paragraphs (2), (3), (4) and (5).

Once the accelerator has been entirely depressed displacing the contact support from its resting position to its operated-position, the operator may release the accelerator partly without returning the contact springs to resting position;

This is so because of the provision of the lostmotion connection between the accelerator and the member 69'. Upon a complete release of the accelerator the contact springs are not re-set to normal until the contacts lid and 12d have been closed,

(8) Another condition arises when the driver releases the pedal 20!! entirely while the vehicle is in operation with the transmission being set to one of its four positions. In this event, the

.two switches lid and 12d are closed by action of the stops l8, after the member 69has been reset to its normal position if it was in operated position before. The closing of the switches lid and 1211 will short-circuit the two relays II and 12. Therefore, the armatures Ho and 120 will stay in their position and will maintain the transmission in the same condition as before. Any gear shifting operation is thus prevented until the accelerator is depressed again. This holds true even though the speed of the vehicle will drop causing the actuator 65 to return towards its resting position.

This is an important feature of my invention as it ensures that, when the vehicle is being driven downhill in 1st gear, the operator may release the accelerator entirely without risking any undesirable gear shifting operation. The

transmission will stay in 1st gear so that the engine may act as a brake. Only when the driver depresses the pedal 209 again; will the shortning with the transmission set to its 4th gear pontion and when the accelerator is then entirely released. the transmission will stay in this position even though the speed of the vehicle will 4 drop. A gear shifting operation will not take gizing current will not be supplied again until the engine has been sped up to a predetermined number of revolutions.

The mechanism shown in Fig. '5 comprises a relay 36 connected with the positive terminal of the customary generator 45-of the vehicle. This generator is provided with a back-current switch R which prevents the battery 15 from discharging through the generator when thesame is inactive.

The second relay 31is connected by a wire 46 with the positive terminal of the battery 15. A working contact 39 ofthe relay 3! is connected with the wire 54 shown in Fig. 3. .Moreover, the

relay 3'! has a normal contact 40 connected with a signal lamp 44. The mechanism also includes a switch 42 which is normally open but isclosed working contact 39 is open and the wire 54. is

dead disabling the transmission. This condition is indicated by the lamp 44. When the operator starts the vehicle accelerating the generator 45 and depressing the clutch 43, the switch 42 is closed establishing the following circuit: battery 15, wire 45, relay 31, wire 41, switch 42, wire, ground. The armature 38 is attracted connecting the working contact 39 with the wire 43 whereby voltage is applied to the wire 54 rendering the transmission operative. At the same time, the following circuit is established: generator 45, relay 33, switch 42, wire 4|, ground. As the generator now produces current, the relay 361s energized closing a holding circuit through its armature 34 and its contact 35 to the groimd,

circuits of the relays 11 and 12 be cancelled Hence, the circuit through relay 3'! is maintained through wire 41, armature 34 and contact 35. The transmission will be disabled again automatically as soon as the speed of the engine drops to the limit where the generator 45 ceases to produce a voltage suflicient to energize the relay 33. The disabling of the transmission interrupts the operative connection between the engine and the driven wheels of the vehicle so that the engine is prevented from being stalled.

I may provide an indicator showing the operator the positions of the accelerator pedal at which the displacement of the contact springs oom-' mences. To this end, means maybe provided increasing the resistance exerted by the accelera- .to actuate the elements of the transmission to set up diflerent ratios of transmission, a plurality of movably supported electrical contacts in normally open electric circuits with said electromagnets, a lost motion connection between said contacts and said eccelerator adapted to displace said contacts to one or the other of two operative positions when said engine accelerator moves into one or the other of its extreme positions, and a circuit maker movable'parallelly of the movement of and relative to said contacts from and in correspondence with variations in the speed of the engine to selectively establish circuits through said contacts and energization of the electromagnets.

2. In means for automatically controlling a variable speed power transmission mechanism of motor vehicles having a plurality of electromagnets operative when energized in different combinations to actuate the elements of the transmission mechanism to set up different ratios or transmission, a movably supported element including a plurality of electrical contacts normally in open circuit with said electromagnets, and a circuit making element movable in the direction of movement of and relative to the contacts adapted to close a circuit through said contacts, one of said elements having a lost motion connection with and actuated by the engine accelerator of the vehicle in opposite directions, the lost motion amounting to the greater part of the stroke of said accelerator, and the other element movable from the engine in correspondence with variations in the engine speed and selectively establish circuits through said contacts and circuit making element and energizing of the electromagnets.

3. In means for automatically controlling a variable speed power transmission mechanism of motor vehicles having a plurality of electromagnets operative when energized in difierent combinations to actuate the elements of the transmission mechanism to set up different ratios of transmission, a plurality of contacts in normally open circuit with. the electromagnets of the transmission, a circuit maker, carriers for said contacts and circuit maker supported to position the circuit maker adjacent the contacts and have movement in the same direction and one relative to the other, one of said carriers being settable to either one of two operative positions by movement of the accelerator of the .engine to its extreme positions and being adapted to remain in its set position until the accelerator moves to its other extreme position, and the other of said carriers movable from and in correspondence with variations in the engine speed and thereby selectively establish circuits through the contacts and circuit maker and energization of-the electromagnets;

' accelerator for the engine of the vehicle operative when the accelerator is substantially in position of rest to render inactive circuits established through the contacts to energize the electromagnets and render said circuits active to energize the electromagnets by the engine accelerating movement of the accelerator.

5. In means for automatically controlling a variable speed power transmission mechanism of motor vehicles having a plurality of electromagnets operative when energized to actuate elements of the transmission mechanism to vary the ratios of transmission, a plurality of contacts normally in open circuit with the electromagnets of the transmission mechanism, a circuit maker, carriers for said contacts and circuit maker supported to position the circuit maker adjacent the contacts and have movement in parallel planes in the same direction and one relative to the other, one of said carriers having a lost motion connection with and actuated by the accelerator for the engine of the vehicle in opposite directions, and the other of said carriers movable from the engine in correspondence with variations in the engine speed and thereby selectively establish circuits through the contacts and circuit maker and energization of the electromagnets, and means automatically operative when the accelerator is substantially in position of rest to render inactive established circuits energizing the electromagnets and operative by the accelerator when actuated to accelerate the operation of the engine to render said circuits active.

6. In motor vehicles, a variable speed transmission mechanism driven from the engine of the vehicle having a plurality of electromagnets connected in a plurality of open electric circuits operative when energized to actuate elements of the transmission mechanism to vary the ratio of transmission, circuit closing means operative to selectively close said circuits, a plurality of relays interposed in the circuits operative to change the circuit arrangement and energization of said electromagnets to actuate the elements of the transmission mechanism to set up different ratios of transmission, means automatically operative when the accelerator is substantially in position of rest to render inactive the established circuits energizing the electromagnets and operative by the accelerator when actuated to accelerate the operation of the engine to render said circuits active.

7. In means for automatically controlling a variable speed power transmission of motor vehicles having a plurality of electromagnets operative when energized in different combinations to actuate elements of the transmission mechanism to set up different ratios of transmission, a battery, a plurality of contacts connected in open circuit with said electromagnets and battery, a circuit maker operative to selectively close circuits through said contacts and energize the electromagnets, a generator driven by the engine'of the motor vehicle, and means interposed in the connection of the battery with said contacts responsive to the voltage produced by said generator and operative when said voltage drops below a certain limit to interrupt said connection of the battery with the contacts and render the transmission inactive.-

8. In a motor vehicle, a variable speed power transmission mechanism driven by the engine of the vehicle having a plurality of electromagnets connected in normally open electric energizing circuits operative when energized to actuate means to effect variations in the ratios of transmission, means including a lever for accelerating the operation of the engine, circuit mak- --ing means in the electromagnet energizing circuits, one element thereof having a two-way lost motion connection with the accelerator leverto transmit the movement of said lever in both directions-and near the ends of its stroke to said element and adapt the accelerator lever to have movement independent of said element during the initial portion of the accelerator actuating and return movements of the lever and before transmitting movement thereof to -said element, and the other element movable from the engine in correspondence with variations in the speed of the engine relative to and co-operating with the first element to selectively close said circuits and energize the electromagnets.

9. In a motor vehicle, a variable speed power transmission mechanism driven by the engine of the vehicle having a plurality of electromagnets connected in normally open electric energizing circuits operative when energized to actuate -means to effect variations in the ratios of transenergizing circuits inactive to energize the electromagnets and operative by the accelerator lever in the accelerator actuating movement thereof to render said circuits active to energize the electromagnets.

10. In a motor vehicle, a variable speed power transmission mechanism driven by the engine of the vehicle having a plurality of electromagnets operative when energized to actuate means to effect variations in the ratios of the transmission, means to accelerate the operation of the engine including an actuating lever, a battery connected in a plurality of open circuits with the electromagnets, circuit making means to control the .closing of said circuits and energizing of the electromagnets, one element thereof connected to and movable by the accelerator lever and the other element thereof movable from the engine in correspondence with variations in the speed 'of the engine relative to and co-operating with the first element to selectively close said circuits and energize the electromagnets, and means interposed in the connection of the battery and electric energizing circuits operative by the englue to open and maintain said connection including means to indicate the open condition of said connection. v

11. Means for automatically controlling variable speed transmission mechanism as claimed in claim 3, wherein the contacts comprise resilient members mounted on the carrier in spaced alined pairs arranged in stepped rows transversely of the movement of the carrier, and the circuit maker comprises an electromagnet extending transversely of the rows of contacts and adapted to attract the contacts thereto.

- v JACQUES NOUGAROU'. 

